Low-flow emitter

Abstract

A low-flow emitter includes a first housing and a second housing. The first housing includes a first thread portion, and a first passage defined in the first thread portion. The second housing includes a second thread portion, and a second passage defined in the second thread portion corresponding with the first thread portion in a thread connection. Part of the thread connection between the first and second housings is a loose fitting thread connection. A spiral passage is formed along the loose fitting thread connection between the first and second housings. Water flow rate is able to be controlled by a rotation of the first housing with respect to the second housing.

What is claimed is: 
     
         1 . A flow emitter comprising:
 a first housing including a first thread portion; the first thread portion including a first thread section and a second thread section;   a second housing including a second thread portion; the second thread portion including a third thread section corresponding with the first thread section of the first thread portion of the first housing, and a fourth thread section corresponding with the second thread section of the first thread portion of the first housing; the second housing connecting the first housing while the fourth thread section of the second thread portion of the second housing engaging with the second thread section of the first thread portion of the first housing;   a spiral passage defined between the third thread section of the second thread portion of the second housing and the first thread section of the first thread portion of the first housing;   a first passage formed on the first housing and communicating with the spiral passage; and   a second passage formed on the second housing and communicating with the spiral passage, and the spiral passage via at least one orifice radially formed on the second thread portion and arranged between the third and fourth thread sections;   wherein the water flows from the second passage through the at least one orifice to the spiral passage, and then enters the first passage for water distribution.   
     
     
         2 . The flow emitter as claimed in  claim 1 , wherein the first housing includes an exterior thread bore, in which the first thread portion is formed; the exterior thread bore defines a diameter, and an end communicating with the first passage; the diameter of the exterior thread bore gradually increases in a direction away from the first passage and tapers off; the second housing includes an exterior thread axle, on which the second thread portion is formed, and the exterior thread axle defines a diameter, and the diameter of the thread axle gradually increases in a direction away from the first passage and tapers off. 
     
     
         3 . The flow emitter as claimed in  claim 2 , wherein the first and second thread sections are formed on the first thread portion of the first housing and connected with each other; the third and fourth thread sections are formed on the second thread portion of the second housing and not connected with each other. 
     
     
         4 . The flow emitter as claimed in  claim 3 , wherein the first and third thread sections are formed of round threads. 
     
     
         5 . The flow emitter as claimed in  claim 1 , wherein the third thread section of the second housing defines a crest with a crest height, and the first thread section of the first housing defines a root with a thread depth; the crest height of the third thread section of the second housing is less than the thread depth of the first thread section of the first housing, and the spiral passage is formed between the crest of the third thread section of the second housing and the root of the first thread section of the first housing. 
     
     
         6 . The flow emitter as claimed in  claim 5 , wherein the first housing includes an end member, a circumference member bordering a periphery of the end member, a tubular head extending from an exterior face of the periphery of the end member in a direction away from the end member, and an exterior thread bore extending from an interior face of the periphery of the end member in a direction away from the end member; the first passage is formed in the tubular head, the first thread portion is formed on the exterior thread bore; the second housing includes a flange retaining against an end of the exterior thread bore of the first housing; the second thread portion extends from the flange in a direction away from the flange. 
     
     
         7 . The flow emitter as claimed in  claim 1 , wherein the first thread portion of the first housing is a thread bore; the thread bore defines a diameter, and an end communicating with the first passage; the first thread section is formed on the thread bore; the second thread portion of the second housing is a thread axle with a diameter; the third thread section is formed on the second thread portion. 
     
     
         8 . The flow emitter as claimed in  claim 7 , wherein the diameter of the first thread portion increases gradually in a direction away from the first passage and tapers off; the diameter of the second thread portion increases gradually in a direction away from the first passage and tapers off.